Filter



may 4, 1937,

F. MANNING FILTER Filed July 30, 1936 2 Sheets-Shea?l l IN VENTOR.

' May 4, 1937. F. MANNING 2,079,297

FILTER Filed July 30, 1936 2 Sheets-Sheet 2 v SS uw wi N [wil n INVENTOR.

Patented May 4, 1937 UNITED STATES PATENT OFFICE FILTER Application July 30, 1936, Serial No. 93,324

8 Claims.

My invention relates to ltering devices, and more particularly to a composite filter of the type used to remove solid particles entrained in a stream of gas flowing therethrough; for example,

a lter of thetype adapted to be arranged across a Ventilating passage for removing dust, dirt, pollen, etc. from a stream of air flowing through the passage.

The objects of my invention are comprised in the provision of a composite iilter which is of improved construction; one which abstracts an unusually large percentage of the solid particles ,entrained in a gas stream yet oiers a minimum of resistance to the ow of the gas therethrough;

l5 and one which is comparatively inexpensive to manufacture, and is unusually strong and durable and will continue to operate effectively and efllciently until its passages are filled with the abstracted solid particles, even though it may be exposed to rain and snow. .l

The invention consists in the novel construction and combination of parts, to be more fully describedhereinafter, and the novelty of which will be particularly pointed out and distinctly claimed.

In the accompanying drawings, to be taken as a part of this specii'lcation, I have fully and clearly illustrated a preferred embodiment of my invention, in which drawings- Fig.v 1 isan elevation showing my improved form of composite filter with a. portion of the flitering element broken away to disclose the combined spacing and stiffening means for the filter;

Fig. 2 is an enlarged fragmentary sectional view 85 taken on the line 2-2 of Fig. 1;

Fig. 3 is an enlarged fragmentary view illustrating the means for securing together the metallic frame for the filter;

Fig. 4 is an enlarged front elevation of the structure at the lower right-hand corner of Fig. 1 with parts being broken away and shown in section to illustrate lmore clearly the means for securing the frame together, illustrated in Fig. 3;

Fig. 5V is an elevational view illustrating the manner in which the frame is assembled about the remaining parts of the composite filter;

Fig. 6 is an enlarged sectional view o n the line 6-6 of Fig. 2 and illustrating more clearly the combined spacing and stiiening means; and

Fig. 7`is anl enlarged fragmentary sectional view taken on the same plane as Fig. 2, but show- Iing a modified form of frame.

Referring now in detail to the co.' ,truction illustrated, it will be observed that I have shown 55 my invention as embodied in a composite or uni- (Cl. 18S-69) tary iilter I0 which is adapted to be arranged across a gas pass and is provided with a multitude Aofpassages extending therethrough and operates to abstract solid particles entrained in the gas as it iiowgl through the passages.

Thev compositefilter comprises a illter proper II and a metallic frame I2 extending about the periphery of the filter proper and securely holding the elements of the. latter in their proper relative positions.

The filter proper is formed oi' a pair of similar ltering elements I3 and I4, each element being provided with passages I5 for the flow of air or gas therethrough, with the passages I5 of one element I3 being arranged at angles to the passages I5 of the other element Il so as to provide tortuous paths for the iiow of air therethrough. The ltering elements I3 and Il are arranged and held in spaced parallel relation, as shown in Fig. 2, by means of an improved form of spacing and stiffening means I6 and staples I1 extending through the filtering elements I3 and Il and the spacing and stiffening means I6.

As will be observed from examination oi Fig. 4, each of the filtering elements is composed of a. plurality of strips I8 of corrugated exible absorbent material. The corrugated strips I8 are separated by straight strips I9, and the strips I8 and I9 are firmly secured together by any suitable means, such, for example, as an adhesive.

The corrugated strips I8 andthe straight strips I9 are arranged edgewise to the direction of vflow of the gas, and the corrugations IB provide the passages I5 for the flow of the gas through the lter. While any number of materials may be found which are iiexible and absorbent, without departing from the scope of the present invention, I have found that paper is admirably suited for this purpose, as it is inexpensive and may be easily corrugated. The paper may be iireproofed if desired.

The surfaces of the illtering elements I3 and I4 may be coated with a suitable viscous material such as oil, so that the solid particles in the gas will stick to the sides of the passages I5 as the gas iiows therethrough. As the' passages I5 oi one iilter element I3 are arranged at angles to the passages I5 oi the other element Il, tortuous psages are provided through the illter which cause the solid particles to be thrown against the oil-coated sides of the passages and thereby increase the eiiiciency of the iiiter. The spacing of the filter elements also aids in the abstracting of solids from the gas, as it provides a break in the air passages and permits formation of the flanges, so as to permit the -The frame I2 provides afl-suitable means for.

holding the i/lter proper and preventing any damage thereto when it is being handled or inserted in position in a gas pass. The frame I2? is preferably formed from a single strip of metal which is formed with flanges 20 which engage the outer faces of the elements at the periphery. Notches 2| are cut in the metal previous to the frame to be bent into a rectangular frame (see Fig/ The free ends of the framel'may be secured' together by any suitable means, for example by tabs 22 formed on one of the free ends and extending through a slot 23 formed in the other free end, and then by bending the tabs in opposite directions as indicated in Figs. 3 and 4.

In accordance with the present invention, I provide an improved form of spacing and stillening means. This means is preferably a sheet of expanded metal coextensive in size with the filtering elements I 3 and I4 and held in close engagement with the opposed inner faces of said lteringelements. I have found that the expanded metal eifectively performs the combined function of spacing the 'filter elements and of stiii'eningy a lter of the type which is made of flexible absorbent material, so that the ilter willnot warp or the strips composing the filtering elementsl will not separate when the illlter is placed in position, even though it be subjected to the deteriorating eiIect of the rain or snow. I am aware'that composite lters have been heretoforeproducedgwhich are 'provided with spacing means between the filtering elements: but, so

v far as I know, an e nded met-al sheet has not been used. The exp nded metal is compara.- tively inexpensive, and by virtue of its peculiar ,formation is sufciently thick to provide the proper spacing between the elements, and due toits rigidity provides an effective and inexpensive stiifener for the lter.

In Fig. 7 of the drawings, I have shown a mod- `iiied formof frame I2a for the filtering element.

The frame I2a shown in Fig. 7 is of the same type as the frame I2 of the previously described modiiication, and in addition is provided with inturned flanges 25 at the inner edges thereof which are pressed into engagement with the outer faces of the filtering element I3a and Ila and serve to both secure the iiltering elements together and to provide a protecting frame thereabout. With the inturned flanges, the majority of the securing staples may be omitted.

From the above description, it will be readily opposed faces vin closely spaced relation and each t element having a multitude of air. passages: extending therethrough; a combined spacing and stiifening means arranged between saidl elements andcomprising a sheet of expanded metal arranged parallel to and engaging at opposite sides thereof the inner faces of said elements; and means for securely fastening the elements and expanded metal sheet together to form an inseparable unit.

2. A composite air filter comprising, in combination, a pair of similar filtering elements arranged parallel to one another with their inner opposed faces in closely spaced relation and each element having a multitude of air passages extending therethrough; the air passages of one of said elements being arranged at angles to the air passages extending through the other of said f elements so as .to provide tortuous paths for the ow of air through said ltering-elements; a combined spacing and stiffening means arranged between said elements and comprising a sheet of expanded metal varranged parallel to and engaging at opposite sides thereof the inner faces of said elements; and means for securely fasten-l ing the elements and expanded metal sheet together to form an inseparable unit.

3. A composite air lter comprising, in coinbination, a pair of similar iiltering elements arranged in .parallel relation to one another with their inner opposed faces in closely spaced relation; each of said elements being formed of an absorbent brous material and having a multi-v tude of passages extending therethrough; a combined spacing and stiffening means arranged between said elements and comprising a sheet of expanded metal arranged parallel to and .engaging at opposite sides thereof the inner faces of said elements; and metuzisl for securely fastening the elements and expanded metal sheet together to form an inseparable unit.

4. A composite air nl ter comprising, in combination, a pair of similar ltering elements arranged .in parallel relation to one another with their inner opposed faces in. closely spaced relation; each of said elements being formed of a plurality of strips of corrugated iibrous material securely iixed together and arranged with the corrugations dening a multitude of passages extending through the elements; a combined spacing and stiffening vmeans arranged between said elements and comprising a sheet of expanded metal arranged parallel to and engaging at opposite sides thereof the inner faces of said elements; and means for securely fastening the elements and expanded metal sheet together to form an inseparable unit.

5. A composite air lter comprising, in combination, a pair of similar iiltering elements arranged parallel to o ne another with their inner opposed faces in closely spaced relation and each :sol

element having a multitude of air passages ex' opposed faces in closely spaced relation and each element having a multitude of air passages extending therethrough; a combined spacing and stiilening means arranged between said elements and comprisinga -sheeiaof expanded metal arranged parallel to and eng g at opposite sides thereof the inner faces of delements; '75

amaze? and stapling means extending through said elements and expanded metal sheet for securely fastening the three together as a unit.

7. A composite air ilter comprising, in combination, a pair of similar ltering elements arranged parallel to one `another with their inner opposed faces in closely spaced relation and each element having a multitude of air passages extending therethrough; a combined spacing and 10 stiiening means arranged between said elements and comprising a sheet of expanded metal arranged parallel to and engaging at opposite sides thereof the inner faces of said elements; and metallic frame means extending about the pe- 15 riphery of said elements and having flange portions engaging the exterior faces thereof for securely holding the 'elements and expanded metal sheet together as a unit.

8. A composite air lter comprising, in combination, a pair of similar ltering elements arranged parallel to one another with their inner opposed faces in closely spaced relation and each element having a multitude of air passages extending therethrough; a combined spacing and stiening means arranged between said elements and comprising a sheet of expanded metal arranged parallel to and engaging at Opposite Sides thereof the inner faces of said elements; stapling means extending through said elements and expanded metal sheet for securely fastening the three together as a unit; and metallic frame means extending about the periphery of said elements and including flange portions engaging the exterior faces thereof, and thereby aiding in securely fastening the elements and expanded metal sheet together.

FOWLER MANNING. 

